```css
:root {
  --bg-primary: #f0f4f8;
  --bg-card: #ffffff;
  --bg-footer: #0b1a2e;
  --text-strong: #1F2937;
  --text-heading: #0b1a2e;
  --text-body: #2d3a4a;
  --text-muted: #4a5a6a;
  --text-link: #1e4b7a;
  --text-btn: #ffffff;
  --accent: #1b5a8a;
  --accent-dark: #0f3b5c;
  --border-light: #d0d9e2;
  --shadow: 0 8px 20px rgba(0,0,0,0.04);
  --dark-bg: #0f172a;
  --dark-card: #1e293b;
  --dark-text: #E2E8F0;
  --dark-heading: #F8FAFC;
  --dark-muted: #B0BEC5;
  --dark-link: #7EB8E0;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg-primary);
  color: var(--text-body);
  line-height: 1.7;
  transition: background 0.3s, color 0.3s;
  background-image: radial-gradient(circle at 10% 20%, rgba(27, 90, 138, 0.03) 0%, transparent 40%),
                    radial-gradient(circle at 90% 80%, rgba(27, 90, 138, 0.03) 0%, transparent 40%);
}

body.dark {
  background: var(--dark-bg);
  color: var(--dark-text);
}

h1, h2, h3, h4 {
  color: var(--text-heading);
  font-weight: 700;
  line-height: 1.3;
}

body.dark h1, body.dark h2, body.dark h3, body.dark h4 {
  color: var(--dark-heading);
}

h1 {
  font-size: 2.6rem;
  margin-bottom: 0.8rem;
}

h2 {
  font-size: 2.0rem;
  margin: 2.2rem 0 1.2rem;
  border-left: 6px solid var(--accent);
  padding-left: 1rem;
  background: linear-gradient(90deg, rgba(27, 90, 138, 0.08) 0%, transparent 100%);
  padding-top: 0.3rem;
  padding-bottom: 0.3rem;
  border-radius: 0 12px 12px 0;
}

h3 {
  font-size: 1.5rem;
  margin: 1.8rem 0 0.8rem;
}

h4 {
  font-size: 1.2rem;
  margin: 1.2rem 0 0.5rem;
  color: var(--accent);
}

body.dark h4 {
  color: var(--dark-link);
}

p {
  margin-bottom: 1.2rem;
  color: var(--text-body);
}

body.dark p {
  color: var(--dark-text);
}

a {
  color: var(--text-link);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

body.dark a {
  color: var(--dark-link);
}

a:hover {
  text-decoration: underline;
  color: var(--accent);
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 导航 */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  transition: background 0.3s, box-shadow 0.3s;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.03);
}

body.dark .navbar {
  background: rgba(15, 23, 42, 0.85);
  border-bottom: 1px solid #1e2a3e;
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 0;
}

.brand {
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--text-heading);
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

body.dark .brand {
  color: var(--dark-heading);
  background: linear-gradient(135deg, #7EB8E0, #4a90b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.menu {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.menu a {
  font-weight: 600;
  color: var(--text-body);
  position: relative;
  padding: 0.3rem 0;
}

body.dark .menu a {
  color: var(--dark-text);
}

.menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s;
}

.menu a:hover::after {
  width: 100%;
}

.menu a:hover {
  color: var(--accent);
  text-decoration: none;
}

.nav-actions {
  display: flex;
  gap: 0.8rem;
  align-items: center;
}

.search-box {
  display: flex;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 40px;
  padding: 0.2rem 0.2rem 0.2rem 1rem;
  transition: box-shadow 0.3s, border-color 0.3s;
}

body.dark .search-box {
  background: var(--dark-card);
  border-color: #2d3a4a;
}

.search-box:focus-within {
  box-shadow: 0 0 0 3px rgba(27, 90, 138, 0.15);
  border-color: var(--accent);
}

.search-box input {
  border: none;
  background: transparent;
  font-size: 0.95rem;
  width: 180px;
  color: var(--text-body);
  outline: none;
}

body.dark .search-box input {
  color: var(--dark-text);
}

.search-box button {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 40px;
  padding: 0.4rem 1.2rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}

.search-box button:hover {
  background: var(--accent-dark);
  transform: scale(1.02);
}

.dark-toggle, .menu-toggle {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 40px;
  padding: 0.4rem 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}

.dark-toggle:hover, .menu-toggle:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

.menu-toggle {
  display: none;
}

/* 移动菜单 */
@media (max-width: 768px) {
  .menu {
    display: none;
    flex-direction: column;
    width: 100%;
    background: var(--bg-card);
    position: absolute;
    top: 60px;
    left: 0;
    padding: 1rem;
    box-shadow: var(--shadow);
    border-radius: 0 0 16px 16px;
  }
  
  body.dark .menu {
    background: var(--dark-card);
  }
  
  .menu.open {
    display: flex;
    animation: slideDown 0.3s ease;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .search-box input {
    width: 120px;
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* hero */
.hero {
  background: linear-gradient(145deg, #0b1a2e, #0f2c44, #1a3a5c);
  color: white;
  padding: 4rem 0;
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.05) 0%, transparent 70%);
  animation: float 8s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(5deg);
  }
}

.hero .container {
  position: relative;
  z-index: 1;
}

body.dark .hero {
  background: linear-gradient(145deg, #0f172a, #1a2538, #1e293b);
}

.hero h1 {
  color: #ffffff;
  font-size: 3rem;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.hero p {
  color: #e2e8f0;
  font-size: 1.3rem;
  max-width: 700px;
  opacity: 0.9;
}

.hero .btn-group {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.btn {
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: white;
  padding: 0.8rem 2rem;
  border-radius: 60px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 4px 15px rgba(27, 90, 138, 0.3);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(27, 90, 138, 0.4);
  color: white;
}

.btn-outline {
  background: transparent;
  border: 2px solid white;
  color: white;
  box-shadow: none;
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: white;
  color: white;
}

/* 卡片 */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.card {
  background: var(--bg-card);
  padding: 1.8rem;
  border-radius: 24px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-light);
  transition: transform 0.3s, box-shadow 0.3s;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

body.dark .card {
  background: var(--dark-card);
  border-color: #273549;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
}

.card h3 {
  margin-top: 0;
  position: relative;
}

.card h3::after {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent);
  border-radius: 2px;
  margin-top: 0.5rem;
}

.card p {
  margin-bottom: 0.4rem;
}

/* 文章列表 */
.article-list {
  display: grid;
  gap: 1.5rem;
}

.article-item {
  padding: 1.5rem;
  background: var(--bg-card);
  border-radius: 16px;
  transition: transform 0.3s, box-shadow 0.3s;
  border: 1px solid var(--border-light);
}

body.dark .article-item {
  background: var(--dark-card);
  border-color: #273549;
}

.article-item:hover {
  transform: translateX(5px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
}

.article-item h3 {
  margin-bottom: 0.5rem;
}

.article-item time {
  color: var(--text-muted);
  font-size: 0.9rem;
  display: inline-block;
  background: rgba(27, 90, 138, 0.08);
  padding: 0.2rem 0.8rem;
  border-radius: 20px;
  margin-bottom: 0.5rem;
}

/* FAQ */
.faq-item {
  background: var(--bg-card);
  border-radius: 16px;
  padding: 1.2rem 1.5rem;
  margin-bottom: 1rem;
  cursor: pointer;
  transition: all 0.3s;
  border: 1px solid var(--border-light);
}

body.dark .faq-item {
  background: var(--dark-card);
  border-color: #273549;
}

.faq-item:hover {
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.faq-question {
  font-weight: 700;
  color: var(--text-heading);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

body.dark .faq-question {
  color: var(--dark-heading);
}

.faq-question span {
  font-size: 1.5rem;
  color: var(--accent);
  transition: transform 0.3s;
  display: inline-block;
}

.faq-item:hover .faq-question span {
  transform: rotate(90deg);
}

.faq-answer {
  margin-top: 0.8rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--border-light);
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-5px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* footer */
.footer {
  background: var(--bg-footer);
  color: #cbd5e1;
  padding: 3rem 0 2rem;
  margin-top: 4rem;
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.footer .grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.footer a {
  color: #a0b8cc;
  transition: color 0.2s;
}

.footer a:hover {
  color: white;
  text-decoration: none;
}

.footer h4 {
  color: #dbeafe;
  margin-bottom: 1rem;
}

.copyright {
  text-align: center;
  border-top: 1px solid #1e2a3e;
  padding-top: 2rem;
  margin-top: 2rem;
  color: #9aaebf;
}

/* 表格、面包屑 */
.breadcrumb {
  display: flex;
  gap: 0.5rem;
  padding: 1rem 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.breadcrumb a {
  color: var(--text-link);
}

body.dark .breadcrumb a {
  color: var(--dark-link);
}

.table-wrap {
  overflow-x: auto;
  border-radius: 16px;
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  border-radius: 16px;
  overflow: hidden;
}

body.dark table {
  background: var(--dark-card);
}

th, td {
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--border-light);
  text-align: left;
  color: var(--text-body);
}

body.dark th, body.dark td {
  color: var(--dark-text);
  border-bottom-color: #2d3a4a;
}

th {
  background: #e9eef3;
  color: var(--text-heading);
  font-weight: 600;
}

body.dark th {
  background: #253244;
  color: var(--dark-heading);
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: rgba(27, 90, 138, 0.03);
}

/* 滚动动画 */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s, transform 0.6s;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 返回顶部 */
.to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: white;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  cursor: pointer;
  border: none;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  z-index: 99;
  transition: transform 0.3s, box-shadow 0.3s;
}

.to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
  background: var(--accent-dark);
}

/* 暗黑模式整体调整 */
body.dark .btn {
  color: white;
}

body.dark .btn-outline {
  border-color: #e2e8f0;
  color: #e2e8f0;
}

body.dark .hero .btn-outline {
  border-color: #e2e8f0;
  color: #e2e8f0;
}

body.dark .footer {
  background: #0b1420;
}

/* 图片占位 */
.svg-img {
  width: 100%;
  height: auto;
  background: linear-gradient(135deg, #dbe4ed, #c8d4e0);
  border-radius: 12px;
}

body.dark .svg-img {
  background: linear-gradient(135deg, #2a3748, #1e293b);
}

.alt-text {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* 响应式优化 */
@media (max-width: 1024px) {
  .footer .grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  h1 {
    font-size: 2.2rem;
  }
  
  h2 {
    font-size: 1.8rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }
  
  h1 {
    font-size: 1.8rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .hero {
    padding: 3rem 0;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .hero p {
    font-size: 1.1rem;
  }
  
  .footer .grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  .card-grid {
    grid-template-columns: 1fr;
  }
  
  .search-box input {
    width: 80px;
  }
  
  .dark-toggle, .menu-toggle {
    padding: 0.3rem 0.8rem;
    font-size: 0.9rem;
  }
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--accent), var(--accent-dark));
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-dark);
}

/* 选中文本样式 */
::selection {
  background: rgba(27, 90, 138, 0.2);
  color: var(--text-heading);
}

/* 焦点可见性 */
:focus-visible {
  outline: 3px solid rgba(27, 90, 138, 0.4);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 卡片内链接 */
.card a {
  display: inline-block;
  margin-top: 0.5rem;
  font-weight: 600;
}

.card a::after {
  content: ' →';
  transition: margin-left 0.3s;
}

.card a:hover::after {
  margin-left: 5px;
}

/* 表格响应式 */
@media (max-width: 600px) {
  .table-wrap {
    margin: 0 -16px;
    padding: 0 16px;
  }
  
  table {
    min-width: 500px;
  }
}

/* 打印样式 */
@media print {
  .navbar, .to-top, .dark-toggle, .menu-toggle, .search-box {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .card, .article-item, .faq-item {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }
}
```